Process for flameproofing cellulosic textiles

ABSTRACT

2-Thia-1,3,5-triaza-7-phosphaadamantane 2,2-dioxide was prepared. The phosphine was converted to the phosphine oxide derivative by reaction with hydrogen peroxide and the methyl phosphonium iodide derivative of the phosphene was prepared by reaction with methyl iodide. Dimethyl sulfoxide solutions of said compounds may be used to flameproof cellulosic textiles.

United States atet 1 Daigle et al.

[451 Aug. 12, 1975 PROCESS FOR FLAMEPROOFING CELLULOSIC TEXTILESInventors: Donald J. Daigle, New Orleans;

Armand B. Pepperman, Jr., Metairie; Gordon J. Boudreaux, New Orleans,all of La.

Assignee: The United States of America, as

represented by the Secretary of Agriculture, Washington, DC.

Filed: May 20, 1974 Appl. No.: 471,5 16

US. Cl 427/396; 106/15 FP; 252/81; 260/243 R; 260/D1G. 24; 427/366;428/276; 428/921 Int. Cl. C091) 5/18; CO7D 295/00 Field of Search.....117/136, 143 R; 260/243 R, 260/248.5, D16. 24; 427/366, 396; 428/921,276; 252/81; 106/15 FP [56] References Cited UNITED STATES PATENTS3,734,684 5/1973 Donaldson et a1 8/183 3,737,284 6/1973 OBrien et a1.8/183 3,745,191 7/1973 Daigle et a1. 260/606.5 P

Primary Examiner-Michael R. Lusignan Attorney, Agent, or FirmM. HowardSilverstein; Max D. Hensley [5 7] ABSTRACT 1 Claim, No Drawings PROCESSFOR FLAMEPROOFING CELLULOSIC TEXTILES This invention relates to ahexamethylenetetramine analog containing sulfur and phosphorus. Morespecifically this invention relates to 2-thia-1,3,5-triaza-7-phosphaadamantane 2,2-dioxide and its derivatives, 2- thia-l,3,5-triaza-7-phosphaadamantane 2,2,7-trioxide and 2-thial ,3.5-triaza-7-methyl-7-phosphoniaadamantane 2,2-dioxide iodide which areuseful as flame retardants for cellulosic textiles and to methods oftheir preparation.

The main object of the instant invention is to disclose the compound2-thia 1 ,3,5-tria2a-7- phosphaadamantane produced by processes of theinstant invention.

A second object of the instant invention is to disclose the derivativesof 2-thia- 1 ,3 ,5-triaza-7- phosphaadamantane 2,2-dioxide, 2-thia-l,3,5-triaza-7- phosphaadamantane 2,2,7-trioxide and 2-thia-l ,3,5-triaza-7-methyl-7-phosphoniaadamantane 2,2-dioxide iodide.

Searching the prior art we find that the process for the preparation oftris( aminomethyl)phosphine is conducted by reacting a secondary aminewith tris(hydroxymethyl)phosphine by itself or in the presence offormaldehyde. [K. A. Petrov, V. .A. Parshina, B. A. Orlov, and G. M.Trypine, Zhur. Obshch. Khem., 32, 4017 1962)]. The prior art also showsthat hexamethylenetetramine or a solution of formaldehyde and ammoniacan be employed rather than simple amines. [D. J. Daigle, A. B.Pepperman, Jr., and S. L. Vail, Serial No. 391,189; filed Aug. 24,1973]. In this prior art a phosphine (C H N P) having the graphicformula can be prepared by reacting tris(hydroxymethyl)phosphine withhexamethylenetetramine, preferably in the presence of formaldehyde.

The amine of the present invention differs from those of the prior artsin that hexamethylenetetramine or ammonia and sulfamide is employedrather than secondary amine. Thus, the phosphine of the present invention is of a new type. In the course of the investigation we have foundthat a phosphine (C H N O PS) having the graphic formula shown below canbe prepared by reacting tris( hydroxymcthyl )phosphine N sq withsulfamide and ammonia or preferably a source of ammonia,hexamethylenetetramine and preferably in the presence of formaldehyde.

In accordance with the present invention the reaction oftris(hydroxymethyl)phosphine with sulfamide and hexamethylenetetramineis carried out by dissolving the rea-ent tris(hydroxymethyl)phosphine informaline (5-10 times the weight of the reagent) andhexamethylenetetramine and sulfamide added and dissolved in the solutionat room temperature. The final solution was allowed to stand at roomtemperature overnight.

This same procedure may be carried out using a solution of ammonia inplace of hexamethylenetetramine. The phosphine product was identified byinfrared and proton magnetic resonance spectra, and by elementalanalysis.

Further, in accordance with the present invention 2- thia-l,3,5-triaza-7-phosphaadamantane 2,2,7-trioxide was prepared by reactionof 2-thia-l,3,5-triaza-7- phosphaadamantane 2,2-dioxide with a peroxidein an appropriate solvent.

In accordance with the present invention2-thial,3,5-triaza-7-methyl-7-phosphoniaadamantane 2,2- dioxide iodidewas prepared by reaction of 2-thia- 1,3,5-triaza-7-phosphaadamantane2,2-dioxide with methyl iodide in an appropriate solvent.

These compounds are useful as flame retardants for cellulosic materialand also as intermediates for other chemical compounds and polymers.Cotton fabric was made flame retardant by impregnating the fabric with a15% dimethyl sulfoxide solution of the compound and drying the fabric.The concentration of the flame retardant may be varied above or below15% depending on the degree of flame retardancy desired.

The following examples illustrate the methods of carrying out theinvention and are included for purposes of illustration, not as alimitation thereof.

EXAMPLE 1 Preparation of 2-thia- 1 ,3,5-triaza-7-phosphaadamantane2,2-dioxide.

Tris(hydroxymethyl)phosphine (3.9 g, 80%, 0.025 moles) was dissolved informalin (20 ml, 40%, 0.267 moles) and water (20 ml). Sulfamide (2.4 g,0.025 mole) and hexamethylenetetramine (3.5 g, 0.025 mole) were addedtogether and dissolved in the solution at room temperature. The solutionheated up slightly and over the next twenty-four hours a precipi tateformed. Filtration, dissolution of the solid in 4 successive 30 mlacetone washes and evaporation of the acetone yielded 3.42 g of crude2-thia-1,3,5-triaza-7- phosphaadamantane 2,2-dioxide (66% yield) [mp274-5 (water)].

Anal. Calcd. for C H N O PS: C, 28.98; H, 4.86; N, 20.28; P, 14.95; S,15.48; mol. wt. 207.2. Found: C, 28.85; H, 4.82; N, 20.26; P, 15.14; S,15.62; mol. wt. 210.

EXAMPLE 2 Preparation of 2-thial ,3,5-triaza-7-phosphaadamantane2,2,7-trioxide.

2Thial ,3 ,5-triaza-7-phosphaadamantane 2,2- dioxide (0.5 g, 0.0024mole) and t-butyl hydroperoxide (70% solution, 0.3 g, 0.0024 mole) werestirred in a 25 ml acetone-25 ethanol solution for 1 hour at roomtemperature. The solution was filtered to yield 0.5 g of crude 2-thia-l,3,S-triaza-7-phosphaadamantane 2.2.7- trioxide (92% yield) [MP 2456(propanol)].

Anal. Calcd. for C H N O PS: C, 26.90; H, 4.52; N, 18.83; P, 13.87; S,14.37; mol. wt. 223.2 Found: C, 27.11; H, 4.55; N, 18.98; P, 14.10; S,14.20; mol. wt. 227.

EXAMPLE 3 Preparation of 2-thia- 1 .3 ,5-triaza-7-methyl-7-phosphoniaadamantane 2,2-dioxide iodide.

2-Thia-1,3,5-triaza7-phosphaadamantane (0.35 g. 0.0017 mole) and methyliodide (0.3 g, 0.002 mole) were refluxed for 24 hours in a m1chloroform-40 m1 ethyl acetate solution. The solution was filtered toyield 0.45 g of crude 2-thia-1,3,5-triaza-7-methyl-7-phosphoniaadamatane 2,2-dioxide iodide (76% yield) [MP 2023 (methylethylacetate)].

Anal. Calcd. for C H -;N O PSI: C, 20.64; H, 3.75; N, 12.04; P, 8.87; S,9.19; 1, 36.35. Found: 20.82; H, 3.75; N, 12.14; P, 8.90; S, 9.34,1,36.52.

EXAMPLE 4 A solution of ammonia may be used in place ofhexamethylenetetramine to prepare 2-thia-l,3,5-triaza-7phosphaadamantane 2,2-dioxide. Tris(hydroxymethyl)phosphine (3.9 g. 80%,0.025 moles) was dissolved in formalin (20 ml, 40%, 0.267 moles) andwater (20 ml). Ammonium hydroxide (29% NH;,, 1.7 ml, 0.025 moles) wasadded to the solution at room temperature. Sulfamide (2.4 g, 0.025 mole)was then added and dissolved in the solution at room temperature. Thesolution heated up slightly and over the next twenty-four hours aprecipitate formed. Filtration, dissolution of the solid in 4 successive30 ml acetone washes and evaporation of the acetone yielded 1.0 g ofcrude 2-thia- 1 ,3,5-triaza-7-phosphaadamantane (19.3% yield).

EXAMPLE 5 Fabric Treatment:

A dimethyl sulfoxide solution containing by weight of2-thia-1,3,5-triaza-7-phosphaadamantane 2,2-dioxide was applied to 8 02.cotton sateen fabric by passing through squeeze rolls to an wet pickupand drying for 4 minutes at C. The fabric had a 12% weight gain and wasflame retardant.

The fabric treatments were evaluated by a well known rapid evaluationflame retardancy test which consists of cutting a small specimen (about1 X 7 cm.) of the fabric to be evaluated, placing the specimen above theflame of a kitchen match with the long axis of the fabric specimen at anangle of 180 to the flame, igniting the specimen (if it can ignite),removing the flaming specimen from the flame, and rotating the specimenuntil the flame is extinguished and recording that angle. (The 0 anglewould be where the flame is at the top of the specimen, and the mostsevere test would be where the flame would be at the bottom. This wouldbe the 180 angle.)

The specimens of Example 1 did not support combustion upon beingsubmitted to this test, that is, the flame was extinguished at a angle;therefore, they passed the flame retardancy test.

The same results were obtained with fabrics treated in the same mannerwith compounds prepared as described in examples (2), (3).

We claim:

1. A process for imparting to a cellulosic textile the quality of flameretardancy, comprising: (a) impregnating the cellulosic textile with adimethyl sulfoxide solution containing about 15% by weight of aphosphine compound selected from the group consisting of 2-thia-1,3,5-triaza-7-phosphaadamantane 2.2-dioxide, 2-thia-1,3,5-triaza7-phosphaadamantane 2,2,7-trioxide, and 2-thia-1 ,2 ,5-triaza-7-methyl-7-phosphoniaadamantane 2.2-di0xide iodide to a wetpickup of about 80%. and (b) drying the wet impregnated textile forabout 5 minutes at about 80C to obtain a treated fabric with

1. A PROCESS FOR IMPORTING TO A CELLULOSIC TEXTILE THE QUALITY OF FLAMERETARDANCY, COMPRISING: (A) IMPREGNATING THE CELLULOISE TEXTILE WITH ADIMETHYL SULFOXIDE SOLUTION CONTAINING ABOUT 15% BY WEIGHT OF APHOSPHINE COMPOUND SELECTED FROM THE GROUP CONSISTING OF2-THIA-1,3,5-TRIAZA-7-PHOSPHAADAMANTANE 2,2-DIOXIDE,2-THIA-1,3,5-TRIAZA-7-PHOSPHAADAMANTANE 2,2,7-TRIOXIDE, AND2-THIA-7-PHOSPHONIAADAMANTANE 2,2-DIOXIDE TO A WET PICKUP OF ABOUT 80%,AND (B) DRYING THE WET IMPREGNATED TEXTILE FOR ABOUT 5 MINUTES AT ABOUT80*C TO OBTAIN A TREATED FABRIC WITH ABOUT 12% WEIGHT GAIN.